Welcome to the NavList Message Boards.


A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding

Compose Your Message

Add Images & Files
    Name or NavList Code:
    Re: Beating a Dead Horse (aka Worley's Sextant)
    From: Brad Morris
    Date: 2014 Jan 18, 22:41 -0500


    I asked about Class A sextants years ago.  No answer, so I cannot pass on an answer I didn't get.

    As to Bill's site.  Yes on figure 3 and yes on figure 4.  In figure 14, I can see the box location for the greatest angle patent, alas, it is empty.  It has the star scope and the 11 x scope. In place of the binoculars, there is a prismatic monocular, which he states he 'added'. The rising telescope piece in figure 7 does not have the collimation adjustment.  When Bill made that piece, he left out that adjustment. His description of the button on the rising piece is correct.  That is the cam that adjusts the height of the scope for the rising telescope feature.  That oddball scope missing from "the" sextant is present in figure 6.  Its the black one.  I think its pretty much the same sextant!  Bill Morris' opinion on the merits of the sextant is most relevant to me.  Thanks, Stan, for pointing this out.

    Mine does provide the patent number.  It was a little hard to read at first but 17840 it is.  Yours *may* be a 'pat. applied for' model from the time before the patent number was assigned.  



    Do you know what the limits of a Class A sextant are?  Mine is also NPL certified as Class A, but it has as much as a 0.4' error (at 75º).

    Is the mechanism for holding the sextant in the box the one described on Bill Morris' site (http://sextantbook.com/2011/12/10/heath-and-companys-best-vernier-sextant/).  In fact, except for the lack of the binoculars and "greatest angle clamp", this looks very similar to yours.  Whether or not it is the model Worsley used, it looks like you have Heath's best vernier sextant, at least according to Bill

    In an earlier message I said that Bill's site said the "endless tangent screw" patent was in 1909.  I now also note from the site that I might have misinterpreted that.  Heath may have applied for the patent in 1909 but did not receive it until March 1910.  It was patent no. 17840.  Does your sextant actually say "Patent 17840" on it?  Mine simply says "Patent" on the tag on the front of the clamp mechanism and on the back of it.


    -----Original Message-----
    From: Brad Morris <bradley.r.morris---.com>
    To: slk1000 <slk1000---.com>
    Sent: Sat, Jan 18, 2014 5:47 pm
    Subject: [NavList] Re: Beating a Dead Horse (aka Worley's Sextant)

    You asked
    The other thing that sticks out is you comment, on more than one occasion, that the sextant used on the JC was ‘with all the bells & whistles’. I think you are just referring to the large scope (which is really not so uncommon)……or are there other features that merit this comment?
    I'll just list all of the features, but before we begin I will point out that there are 3 explicitly patented features, so indicated by the word patent on the feature.
    Sight Tube, no cross hairs
    3 1/2 power erect scope, no cross hairs
    Binocular Attachment
    4 power erect scope (large star scope), no cross hairs
    4 power inverting scope, two cross hairs
    11 power inverting scope, two cross hairs. 
    Telescope shades (2 of differing densities) These fit on most the telescopes by your eye.  Star scope and binoculars excluded.
    "Patent Greatest Angle Clamp".  Rides on the arc while you look for meridian crossing.  Post crossing, the angle declines.  So it indicates the largest angle observed in a series.  Very useful in the Time Sight Era.
    The Key.  Actually present
    Adjusting pin (for mirror adjustment)
    4 colored shades plus astigmatiser on index path (total 5)
    3 colored shades on horizon path
    Ivory inset into handle for note taking
    Silver arc (per inspection certificate) divided to 10 minutes.  0 to 150 degrees, of which only the bottom 125 can be used
    Vernier (likely silver) divided to 10 seconds, 10 minute range.
    Arc microscope
    Arc illumination translucent glass
    Rising telescope feature, on a cam, adjusted by a knob.
    Collimation adjustment for scopes
    Hezzanith Endless Tangent Screw, Automatic clamp, "Patent 17840"
    The arc/index combination has 0 minutes and 0 seconds of error, as measured by National Physical Laboratory, every 15 degrees from 0 to 120.  Its a zero-zero sextant.  The NPL called it a "Class A" sextant.
    I had the mirrors professionally resilvered, using the original glass.
    "Patent" mechanism to hold the sextant in the box.  Requires you to press a mechanical release which locks the sextant into the box.
    Leaf springs under the sextant feet, keeping the sextant from rattling around
    The hooks that keep the box closed, in addition to the lock, have a spring detent.  Kind of like a child proof device, it requires that you press on one part of a spring to release the flat hook to rotate, releasing the lid.
    Functional lock. 
    Every piece or part is present.  Not one item is missing, unlike "the" sextant used by Worsley, which is missing two pieces, as far as I can tell.

    On Jan 18, 2014 12:37 PM, "Brendan Kinch" <brenkinch---.com> wrote:

    Sorry I missed the beginning of this thread or rather the one entitled ‘chasing Shackleton’. I am not really sure where all the talk of the sextant was coming from (or going to) but just happened across a couple of points that I needed to clarify for myself.
    I think from what I can read, is that you wished to point out that you had a similar sextant to that used on the James Caird. In doing so, you wished to point out that the sextant used on the JC was a Heath Hezzanath Triangle Pattern Frame (frame type not mentioned previously though) as per some photos and as shown by the James Caird Society in their exhibit.
    I am with you 100% and very happy for you that you have a similar type sextant.  And I agree, it makes little difference as to who actually owned that particular sextant – it comes down to who used it and for what.
    Having said that there were two things that I questioned in my own mind having seen your last posting. Item #7 – already discussed and needs no more explanation. Only thing here is that we see a photo of Worsley holding a sextant……I do not know the origin of that photo or of any statement saying that it is actually his sextant….but I will just assume it to be his until someone says different. That particular sextant appears to me to be a Heath Hezzanith Bell Frame.
    The other thing that sticks out is you comment, on more than one occasion, that the sextant used on the JC was ‘with all the bells & whistles’. I think you are just referring to the large scope (which is really not so uncommon)……or are there other features that merit this comment?
    Regardless…..I have no problem with overall drift of the thread (now that point #7 dropped) and apologies for coming in the middle without getting to grips with the actual point of the postings.
    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Brad Morris
    Sent: 18 January 2014 17:28
    To: BrenKinch---.com
    Subject: [NavList] Re: Beating a Dead Horse (aka Worley's Sextant)

    If the picture of Worsley holding a sextant, point 7, is excluded then we still are left with points 1 - 6.  Those are the important ones anyway.  They indicate which sextant was used on the journey from Elephant Island to S. Georgia Island.
    I've never much cared who owned the sextant that was used.  That's the fine bit of pish-posh that serves no purpose.  So Hudson owned it.  Did he use it in the navigation?  No!  Was he the navigator? No!  
    I do care what sextant was used.  Its the Heath Hezzanith, with all the bells and whistles, as shown in points 1 - 6.  I do care who used it.  Frank Worsley.  I do care who performed the navigation.  Frank Worsley, unquestionably.
    Thanks for excluding point 7.  Your expertise is most welcome in these quarters.  It was a weak point anyway.  No purpose in including disputable evidence. That only tends to condemn the entire argument. 
    On Jan 18, 2014 7:22 AM, "Brendan Kinch" <brenkinch---.com> wrote:

    Hi Brad/Stan
    This is the first time that I have seen all the information in one spot. In truth I was not following this thread in the earlier part. Going down through your points all seems clear enough and the evidence is there for everybody saying this information all refers to the same sextant.
    THEN I came to your point #7 and the photograph of Frank Worsley holding the sextant. (I had not seen this before).  Here I have to disagree (I must be careful here…….) that everything comes together.
    In my opinion all other photos show a Hezzanith Triangle Pattern frame but the photo of Worsley holding a sextant shows him holding (from what I can see) a Hezzanith Bell Pattern sextant.
    As per George Huxtable in 2009…
    I now have a copy of "Shackleton's Boat", by H M Dunnett, who founded the
    James Caird Society. That provides a picture of the sextant that they claim
    was used by Worsley on the voyage. Not Worsley's own sextant, however; he
    stated that he borrowed Hudson's (Endurance's navigator) for the voyage,
    because he found it easier to use on the boat (without saying why).”
    In my opinion we are seeing these two sextants in this particular thread.
    When looking at the differences between the sextants note the curves on the frame of the one Worsley is holding. In the exhibition the bottom horizontal frame bar is straight. The swing arm for the magnifier is also different…..look close where the swing arm attaches to the index arm to see the different shape in the arms. One other difference I see is that in the photo of Worsley, the sextant appears to have some sort of shade above the horizon mirror. This may or may not have been fixed but I would suggest it is similar to that on the bell frame sextant in National Maritime Museum at Greenwich. (See NAV1166 or Morzer Bruyns book….page216).
    I would be of the opinion that on the photographic evidence, Worsley had a Bell Frame  sextant and as per that being presented by the James Caird Society, Hudson had a Triangle Frame sextant. (But we do know that Worsley used Hudson’s sextant on the James Caird trip).
    I attach a few photos….trying to get the angle right (against a dark background) to simulate the photo of Worsley with his sextant……and to show the curves of the frame. The first darkened as best I can, the last just to show the full Bell Frame sextant (although mine does not have the same swing arm as Worsley nor does it have the horizon mirror top shade).
    From: NavList@fer3.com [mailto:NavList@fer3.com] On Behalf Of Brad Morris
    Sent: 18 January 2014 09:03
    To: BrenKinch---.com
    Subject: [NavList] Beating a Dead Horse (aka Worley's Sextant)

    Summarizing all the findings
    1) Seb's site references a sextant owned by Hudson, loaned to Worsley.  This information is consistent with the information from the James Caird Society, who state the same.  So it references the Heath Hezzanith model without stating exactly that.  Unfortunately, Seb provides a link to a generic sextant wiki page , not an image of "the" sextant. http://www.sebcoulthard.com/navigational-instruments.html
    2) Seb's sight shows an image of the Heath Hezzanith sextant and identifies it as the one Worsley used.  This is confirmed by the Scott Polar Research Institute.  http://www.sebcoulthard.com/navigational-instruments.html (result: same sextant)
    3) Flickr image of the Heath Hezzanith sextant, in detail showing Worsley's name. http://m.flickr.com/#/photos/markbrandon/7220573974/ (result: same sextant)
    4) Image from James Caird Society of the Heath Hezzanith sextant, provided by George Huxtable.  James Caird Society states it was loaned to Worsley by Hudson.  http://fer3.com/arc/m2.aspx/Fw-Image-Sextant-Used-Worsley-Huxtable-mar-2009-g7574 (result: same sextant)
    5) Statements from British Museum     http://forum.thedarkdoor.co.uk/phpBB3/viewtopic.php?f=6&t=344 and the American Museum of Natural History   http://www.amnh.org/exhibitions/past-exhibitions/shackleton/the-exhibition stating that the sextant used by Worsley travels with the James Caird.  Said boat owned by the James Caird Society. (result: same sextant)
    6) image I found on the internet in 2009 of the Heath Hezzanith sextant.  Caption in photo states it was used on journey and was loaned to Worsley by Hudson.  Person who took photo stated that it was with the Caird exhibit.   http://fer3.com/arc/m2.aspx/Image-Sextant-Used-Worsley-Morris-feb-2009-g7412  (result: same sextant)
    7) Image of Frank Worsley holding the Heath Hezzanith sextant with the very specific star scope.  http://fer3.com/arc/img/107418.worsley%201.jpg (result: same sextant)
    No further equivocation can be made.  They all reference the same sextant.  The one that Worsley used on the journey is a Heath Hezzanith, the type with all the bells and whistles.  
    Horse thoroughly beaten.  Maybe I'll compulsively beat it a few more times, just for good measure.  Sooner or later, this topic will arise again and I wanted all the referenced evidence in one spot. 
    My apologies for boring the snot out of you folks.

    On Jan 18, 2014 1:11 AM, "Stan K" <slk1000---.com> wrote:

    Ha!  Good point, Brad.  I have been assuming that the sextant shown in the photograph of Worsley on Chasing Shackleton is the one used on the Caird, but there is no hard evidence of that.

    I believe your sextant matches the one in the photograph, and am happy to trust you that it also matches the one that tours with the Caird!

    Unless someone else comes up with something definitive, I am confused enough to consider this beaten horse very much dead.

    -----Original Message-----
    From: Brad Morris <bradley.r.morris---.com>
    To: slk1000 <slk1000---.com>
    Sent: Fri, Jan 17, 2014 8:07 pm
    Subject: [NavList] Re: Chasing Shackleton

    Seb's site is interesting.  Its obviously the background information to the Chasing Shackleton program.  Interestingly, he never mentions Worsley's navigational log.  You'd think that might be of interest.  It has been posted here on NavList for years.  Maybe he can't decode it.
    My identification is based upon a tourist photograph of the sextant with the James Caird.  It wasn't the best photo but the match was good.  The binoculars matched. The frame matched.  The star scope matched. Particularly telling was the missing scope (of the companion to the Caird) and its holder.  Its a very odd scope.  The optics at the far end are twice in diameter that of the near end.  The scope stands upright in the box.  I've not ever seen one like it (which of course is laughably insufficient evidence) nor its holder.
    I won't die on this hill.  I believe we are encountering specs-manship.  Seb points out the sextant used by Hudson aboard the Endurance (probably true).  Then we have another sextant used by Sir Shackleton (probably true. But now that's TWO sextants pointed at by Seb, which one is true).  Then we have photographic evidence of Worsley holding 'his' sextant.  (Definitely true).  We know that Worsley navigated the Caird (absolutely true).  We have the sextant that tours with the Caird with statement saying this is "the" sextant (probably true).  I think the sextant that tours with the Caird, identified as "the" sextant used, matches mine (trust me, okay? Hahaha).  
    So we have a bunch of 'true' statements but only one sextant can be the one Worsley used.  I cannot understand why Worsley would switch sextants at the juncture of his most critical journey.   He could go with the one he was used to.  He could take Hudson's sextant or he could use Sir Shackleton's and experience another learning curve.  Why?
    Seb also points out two sextants, but fails to mention the sextant with the James Caird.  Why wouldn't he pick just one.  My answer: he suffers from lack of certainty.  Everyone wants to have "the" sextant.  "Come see the actual sextant blah blah blah".  Just like me.  I want a match to "the" sextant used by Frank Worsley, especially if its the one used on "the" journey.  At a minimum, my sextant matches one that we know he used by photographic evidence.  Is it a match the one he used on the Caird.  First we have to identify that one!!

    On Jan 17, 2014 6:42 PM, "Stan K" <slk1000---.com> wrote:


    Comparing your photo to the on of Worsley holding the sextant, it is still hard to tell if they are the same scopes.  However, comparing the relative sizes of the objective lens and the horizon shades, I'd say that it could very well be the same model.

    As to whether the flickr photo is Worsley's sextant or not, the photo may be the same as the one at http://www.sebcoulthard.com/navigational-instruments.html.  The caption reads "Sextant, pocket chronometer, and pocket watch used by Sir Ernest Shackleton & Frank Worsley during the voyage of the James Caird (Scott Polar Research Institute, University of Cambridge)".  It also says

    Instruments used by Shackleton & Worsley
    aboard the James Caird:

    ‘Heath & Co.’ sextant (owned by Lt. Huberht Hudson, navigator onboard Endurance)

    So you be the judge.  Is it Hudson's sextant that was used aboard the Endurance, or was it used by Worsley aboard the James Caird?  The only place where it says
    "Shackleton's Sextant and Chronograph" is with the flickr photo, which also omits mention of the watch.  The sebcoulthard photo also mentions Worsley, so I suspect the flickr photo only says Shackleton because many more people are familiar with that name than with Worsley.

    According to http://www.jamescairdsociety.com/, the Caird is normally preserved and exhibited at Dulwich College, but it has made the rounds.  I can't find anything about the sextant being exhibited with it as a rule, even at the Dulwich College site, although when the Caird was at the American Museum of Natural History in New York, "To the stern of the Caird, in a glass case, was the sextant used by Frank Worsley in his incredible navigational feat."
    -----Original Message-----
    From: Brad Morris <Bradley.R.Morris---.com>
    To: slk1000 <slk1000---.com>
    Sent: Fri, Jan 17, 2014 3:40 pm
    Subject: [NavList] Re: Chasing Shackleton

    Hi Stan
    Here is the sextant with the requested star scope mounted. The optics on this create an erect (non-inverting) image. They are, IMHO, spectacular optics.
    One must be careful with the online image of "Shackleton's Sextant". He was indeed a licensed master and undoubtedly had his own sextant. In my opinion, it would be somewhat ridiculous if Shackleton did not possess a sextant. However, and this is the important distinction, Worsley was the navigator on the expedition, not Shackleton.. So when the display says "Sir Shackleton's Sextant" it is not Worsley's sextant! Worsley's sextant is exhibited with the James Caird.
    NavList message boards and member settings: www.fer3.com/NavList
    Members may optionally receive posts by email.
    To cancel email delivery, send a message to NoMail[at]fer3.com

    Attached File:

    (IMG_20140117_144907.jpg: Open and save)

    Attached File:

    (IMG_20140117_145307.jpg: Open and save)
    Attached File:

    (img/126501.sextant lighting.jpg: Open and save)

    Attached File:

    (img/126501.sam_1057 (1080 x 608).jpg: Open and save)

    Attached File:

    (img/126501.sam_1053 (1080 x 608).jpg: Open and save)

    : http://fer3.com/arc/m2.aspx?i=126529

    Browse Files

    Drop Files


    What is NavList?

    Get a NavList ID Code

    (please, no nicknames or handles)
    Do you want to receive all group messages by email?
    Yes No

    A NavList ID Code guarantees your identity in NavList posts and allows faster posting of messages.

    Retrieve a NavList ID Code

    Enter the email address associated with your NavList messages. Your NavList code will be emailed to you immediately.

    Email Settings

    NavList ID Code:

    Custom Index

    Start date: (yyyymm dd)
    End date: (yyyymm dd)

    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site
    Visit this site